id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
5372,spinlock fails on iPad2,Trantec@…,Peter Dimov,"Hi,

I found an issue with the spinlock in spinlock_gcc.hpp.

In our Project and in my testcode it doesn't work with multithreading on the iPad2 multicored arm processor.

Here is the code which you can use to verify it:

-----------

void doSomething(boost::weak_ptr<int> weakp, int* number)
{
	int i = 0;
	while(++i<10000)
	{
		{
                        /* That works: the result is a number that equals to 40000*/
			/*__sync_fetch_and_add(number, 1);*/

                        /* Here the result is a number much smaller then 40000*/
			/*boost::detail::atomic_increment(number);*/

                        /* This crashes after some time since the use_count is becoming zero*/
			/*boost::shared_ptr<int> p=weakp.lock();*/
		}
	}
}*/

int main(int argc, char *argv[]) 
{
	int iNumber = 0;
	boost::shared_ptr<int> p(new int(0));
	boost::shared_array<boost::thread> t;
	t.reset(new boost::thread[4]);
	for(size_t i=0; i<4; i++)
	{
		t[i] = boost::thread(boost::bind(&doSomething, p, &iNumber));
	}
	
	t[0].join();
	t[1].join();
	t[2].join();
	t[3].join();
}

-------

If you got any questions, don't hasitate writing an email to me :)

Greetings,

Sascha",Bugs,closed,To Be Determined,smart_ptr,Boost 1.41.0,Showstopper,fixed,,